docs: def _fileToMatrix(file_name):
      """rudimentary method to read in data from a file"""
      # TODO: np.loadtxt() might be an alternative
      #     try:
      if 1 < 3:
          lres = []
          for line in open(file_name, 'r').readlines():
              if len(line) > 0 and line[0] not in ('%', '#'):
                  lres.append(list(map(float, line.split())))
          res = lres
      while res != [] and res[0] == []:  # remove further leading empty lines
          del res[0]
      return res
      #     except:
      print('could not read file ' + file_name)